Apparatus for separating ground material, particularly cocoa powder.



E. L. H. BAUERMEISTER. APPARATUS FOR SBPARATING GROUND MATERIAL, PARTIGULARLY 0000A POWDER. APPLICATION FILED D110. 9, 191'2.

1,058,344. Patntea Apr. 8, 1913.

@44mm/w' M ,iA/@Mmmm COLUMBIA PLANQGRAPH CO..WASHINDTON, D. C.

y B. LH. BAUERMEISTBR. APPARATUS FOR SBPARATING GROUND MATERIAL, PARTIGULARLY COCOA POWDER.

APPLICATION FILED DEO. 9, 1912.

1,058,844. Patented Apr. 8, 1913.

2. SHEETS-SHEET 2.

n COLUMBIA PLANOORAPH CO., WASHINUTON. D. t:`

EMIL LUDWIG HERMANN BAUERMEISTER, 0F ALTONA, GERMANY.

APPARATUS FOR SEPARATING GROUND MATERIAL, PARTICULARLY COCOA POWDER.

Specification of Letters Patent.

Patented Apr. s, 191s.

Application filed December 9, 1912. Serial No. 735,824.

To all whom t may concern Be it known that I, EMIL LUDwrG HER- MANN BAUnnMnis'rER, a resident of Altona, near Hamburg, Germany, and subject of the German Emperor, have invented a new and useful Apparatus for Separating Ground Material, Particularly Cocoa Powder', of which the following is a specification.

The present invention relates to an appa-y ratus for separating or sifting ground material particularly cocoa powder and similar products, adapted especially for use in connection with a blast sifting machine having a ventilator or an exhauster and a spreading disk in combination with a dust collector.

During the last few years in the cocoa industry cocoa hasr been freed of more of its oil and fat than formerly, and at the same time it has been the aim to reduce the size of the particles of the cocoa powder as much as possible. Cocoa powder deprived of its oil will not retain its solubility and power of suspension equal to cocoa, not so strongly deprived of oil unless the former is sifted to a finer degree. Though by the aid of sifting apparatus in which very fine sieve gauze is used any desired degree of lineness can be obtained, yet the application of such fine sieves considerably decreases the efficiency quantitatively. Moreover the meshes of the sieves or wire netting become obstructed or smeared on account of the fatty constituents and therefore the sieves have to be renewed several times a day. Therefore it might appear obvious to make use of blast sifting for separating or sifting cocoa, it having given good results in connection with other products.

All blast sift-ing apparatus known heretofore are not adapted to sift cocoaand have the following drawbacks: In the blast sifters known heretofore the current of airy continues to circulate within the sifter in a circle and fresh air is fed to a very little extent, if at all, into the sifter. This constant use of the same circulating current has the drawback that the temperature 'gradually increases, particularly when cocoa powder is treated. It may even happen, that the temperature rises to such an extent, that the melting point of cocoa butter is reached. The consequence is, that the cocoa powder forms balls or lumps and thus impairs or completely destroys the efficiency. The blast sift-er must then be stopped for a while and can only be brought into action again after being cleaned and cooled. The feeding of the materials to be sifted, to the blast sifter takes place either directly from the pulverizing machine or by aid of an elevator, spiral screws or other conveying devices. By these means however it is not possible to obtain an even and uniform feed of the material. The material is rather fed on to the blast sifter more or less intermittently. In blast sifters in which a spreading-or distributing-disk is used, the material is not thrown olf evenly, but it leaves the spreading disk in'the form of an uneven thick horizontal veil which must be crossed by the current of air. The consequence is, that on those places, where the current of air strikes against the thicker parts of the veil the material falls down in a thicker stream than on other places where the veil or mantle of material flung against a dashring is crossed by the stream of air. On those places, Where the material falls down in the thicker stream the current of air cannot separate the finer particles yto a sufficient degree, while on those places where the stream of material is thin or weak the current of air will act to a stronger degree. The irregularity of the veil or mantle of this sifted material is the cause of the line product still containing coarse or coarser particles while the coarse products contain fine powdery substances. In blast sifters in which the spreading disk or plate throws the material against a full dashring the ground products containing fat (such as cocoa powder) frequently adhere or stick very soon to the surface of the dashring on account of the fatty constituents in the material. The stream of air naturally would have no effect on this sticking, adhering material which would finally fall off in larger or smaller lumps. The consequence would be again, that the blast sifter must be thrown out of action' and that the dashring would have to be cleaned. Moreover the blast sifters known heretofore are not adapted to expel from the cocoa powder the fine woolly hairs, which become detached from the press covers or fiannels in producing presscakes. These hairs adhere to presscakes and when the latter are ground hairs are found in4 the ground material. In closely examining such a presscake it is found that the surface is covered with fine short hairs. The specific weight of these hairs is still less than the specific weight of the finest particles of cocoa and then the blast sifter merely carries out a separation according to the weight. rFliese line hairs will be tound in the tinely sitted product. Had these hairs been evenly distributed throughout the whole quantity ot the sitted cocoa powder this unpleasant tact in many eases would not be noticed. However there is the turth-er inconvenience that in using blast sitters these tine hairs always accumulate on certain places and then adhering to small -lumps tall within the cocoa meal. It cocoa meal which is merely produced by the aid ot blast sift-ers is examined microscopically or it the cocoapowder is sitted subsequently through a 4tine sieve the hairs will be readily tound in the meal. The removal ot the hairs trom the cocoa meal is an absolute necessity to meet all demands with regard to thequality and purity.

The drawbacks-explained above are done away with by the present invention, which more particularly reters to t-he separation 4ot cocoa powder. According to this invention a'blast sitting machine having a vent-ilator andfspreading plate is combined with a dust collecting device operating in such manner, that the material, atter being led through a distributing cage is driven by means ot spreading disks through sieves into a vvessel serving as a depositor or collector tor thegritty constituents, the ted material being passed by a current ot tresh air, which moves upward and which may be produced bythe ventilator and regulated with regard to its volume so that it is continuously renewed in such manner that this current ot air carries away the dust or powder ot the ground product. The current ot air thus being saturated with cocoa dust or meal is led into a dust deposito-ry or collector, in which it is deprived ot the dust and trom where it finally escapes into the open air in a clean state.

In the accompanying drawings an apparatus is shown, tor carrying out this invention-by way ot example.

Figure 1 is an elevation ot a complete sitting apparatus embodying my invention. Fig..2 is a plan ot the lower part ot the apparatus. Fig. 3 is-an elevational section ot the blast sitter arranged according to the present invention to a larger scale and Fig. t is a plan ot the sitter shown in Fig. 3.

The blast sitter consists ot a partly cylindrieal and partly conical vessel or chamber o trom which is suspended a collecting cone Z), the upper-part ot which is preterably cylindrical and is provided with a number ot openings c tor allowing tresh air to enter. These openings may be provided with valves or adjustable flaps d similar to Venetian blinds to regulate the entrance ot air and thus the strength ot the current ot air created by the ventilator or exhauster g. Centrally within the chamber a. a spreading disk f is rotatably arranged and above this disk the ventilator and e'xhaustcr g is mounted, irmly connected with the spreading disk so to rotate with it. rl`he disk f is pro vided on its underside with a number ot beating blades or beating wings z, which are surrounded by a preterably coni ral sieve, mantle z' having an outlet spout 7a. This mantle is prolonged upward so as to also surround the rotating disk The material talling on the disk is spread about in the shape ot a. thin veil or mantle, striking againstthe upper part ot the sieve i., and in talling or sliding along the inner surface ot the sieve, the material is distributed over the complete surtace ot the sieve by the beating wings and driven through the meshes ot the sieves and thus blasted into the chamber a. The material entering the space between the sieve c' and the conical wall ot the chamber (L and consisting ot cocoa meal and grit is passed or crossed by an upward current ot tresh air, taking the way indicated by arrows in Fig. 3. The upward moving air will be saturated with the iinest particles ot the material (meal dust) while the coarser part (grit) talls downward and is led away through the outlet ot the collecting cone The meshing ot the sieve mantle should be so chosen` that it allows the mixture ot cocoa meal and cocoa grit to pass, while it holds back the foreign admixtures such as fibers, hairs and the like which may be led awa-y by the outlet tube 7c as waste, while by the aid ot blast sitters known heretotore it was only possible to separate the material into meal and grit. The new apparatus hav ing an inner sieve c' allows ot a triple sorting viz: meal, gritand waste. The latter` consists mainly ot woolly hairs or tibers originated trom the presseovers (cloths) and it is highly important, that such impurities are removed. The torce ot the current ot air entering the chamber a below the sieve i is regulated by the tlaps CZ in such manner that trom the mixture ot meal and grit the meal or dust is carried away through the exhauster g, while the clean grit. is held back by the weight ot its particles and leaves the sitter by way ot the collecting cone Y). In arranging the iiaps or jalousies outside ot the blast sitter the manipulation ot the blast sitter is ver 7 much tacilitated with regard to the regulation ot the current ot the air. Any known means can be employed to adjust the laps. Means ot this description being generally known are not shown in the drawings. By continuously teedingtrcsh air tro-1n outside through the blast sitter an increase ot temperature within the blast 'sitter is avoided. By properly adjusting the flaps the temperature which is most tavorable tor separating cocoa powder can be easily maintained constant. rlhe current ot air when well saturated with meal or material.

powder is led into a dust or powder collecting device n, by the tube m. -In this device the heavier' particles of cocoa are separated from the lighter air by expansion of the latter as is well known and thus the cocoa dust particles are caught below the deposit ing device. The air which is expelled by the pipe e is led into a well known hose-filter :c to clean and deprive the air of any cocoa powder or dust that might have been carried away.

Above the spreading plate f there is arranged a distributing cage p consisting of a perforated mantle and an imperforate bottom, for the purpose of preventing the spreading plate from being charged with the material only on one side by the inlet pipe o which stands at an angle. Within this cage p brushes g and wings r are attached to the upright spindle s of the spreading disk f, so that they rotate together with the disk and move the incoming cocoa powder along the wall of the cage and distribute it through its openings. By these means the cocoa powder is well distributed about the whole circumference of the disk and the veil of powder thrown olf from the disk is evenly blast-ed into the chamber a through the meshes of the sieve c'. Therefore the current of air crossing these streams of powder entering the chamber a will act evenly on the The distributing cage p also serves as a safeguard as any foreign bodies, such as nails, stones and the like, will fall on the bottom of the cage p and come to a rest since they cannot be shifted about by the brushes g or wings 7', the latter do not eX- tend to the bottom. From time to time these foreign bodies can be removed in any convenient manner. The brushes and wings may also serve as agitators for loosening or disintegrating any lumps that may accumulate within the material or to separate smaller particles from the larger by friction.

The operation is as follows: The cocoa cakes which are previously disintegrated or comminuted are fed into a pulverizing machine or mill e by the elevator and on the way they pass a magnetic device u which in usual manner holds metallic impurities back. When well pulverized in the mill e the material is fed on by a conveyer screw w to the inlet 0 and into the blast sifter. From the pipe o the material drops first into the distributing cage p and from here onto the spreading disk f. The lat-ter throws the material readily away and in falling in the shape of a veil the material is caught by the wings z, and driven through the meshes of the sieve z'. The waste material which does not pass the meshes of the sieves, (that is the hairs and fibers) is led away by the pipe la. The material which is blasted through the sieve z' into the chamber a consisting of grit and meal is separated by the current of air entering from outside. That part of the material, which drops down in the chamber a, that is the grit, is collected by the cone b and falls out through its lower spout. The current of air saturated with the cocoa meal or line powder is driven by the exhauster g into the tube m and from here into the dust collecting device n, in which by the expansion of the air the coco-a dust separates from the air and falls down in the collecting vessel.

The hose filter ai is arranged above a prolongation of the conveyer w which is arranged below the pulverizing machine e. One half of the hose g/ serves to filter the warm air created by the pulverizing machine o, while the other half of the hose serves for iltering the air escaping by the pipe e from the dust depositing device n. The dust particles held back by this hose are led away by the outlet z.

I claim:

l. An apparatus for separating ground material, comprising a chamber open at its lower end7 a sieve mounted within the chamber, means to introduce said material into the sieve, revolving blades within the latter adapted to drive the finer parts of said material through the sieve, an outlet spout at the lower end of the latter, and means to create an upward current of air within the chamber outside the sieve and against the material passed through the sieve.

2. An apparatus for separating ground material, comprising a chamber open at its lower end, a sieve mounted within the chamber, means to press the fine parts of said material through the sieve, means to convey the coarser parts of said material from the interior of the sieve, and means to create an air current upwardly through the bottom of the chamber outside the sieve against material passed through the latter.

8. An apparatus for separating ground material, comprising a chamber lopen at its lower end, a sieve mounted within the chamber and terminating above the open end of the latter, means to press the fine parts of said material through the sieve, means to convey the coarser parts of said material from the interior of the sieve and means to create an air current upwardly through the bottom of the chamber outside the sieve against material passed through the latter.

4. An apparatus for separating ground material, comprising a chamber open at its lower end, a sieve mounted within the chamber and terminating above the open end of the latter, means to press the iine parts of said material through the sieve, means to convey the coarser parts of said material from the interior of the sieve, means to create an air current upwardly through the bottom of the chamber outside the sieve against material passed through the latter, whereby the lighter parts of the sifted material are entrained by said current, and a collecting cone below the chamber to receive the material not entrained by the current.

5. An apparatus for separating ground material, comprising a chamber open at its lower end, an air exhaust communicating with the upper `part of the chamber near the periphery thereof, a sieve mounted within the chamber terminating above` the lower end thereof, means to sift the material through the sieve, means to convey waste parts of the material from the interior of the sieve, a collecting cone surrounding the open end of the chamber and provided with air inlets whereby an upwardly directed air current is created by the exhaust within the chamber outside the sieve.

6. An apparatus for separating ground material, comprising a chamber open at its lower end, an air exhaust communicating with the upper part of the chamber near the periphery the eof, a sieve mounted within the chamber terminating above the lower end thereof, means to sift the material through the sieve, means to convey waste parts of the material from the interior of the sieve, a collecting cone surrounding the i open end of the chamber and provided with inlets above the open end of the chamber, whereby air is sucked downward into the collecting cone and upward through the chamber outside the sieve.

7. An apparatus for separating ground material, comprising a chamber, a collecting cone surrounding the lower port-ion of the chamber and communicating therewith through the bottom of the latter, a sieve mounted in the chamber forming an annular passage above the bottom of the latter, means to introduce ground material into the sieve, revolving blades within the latter adapted to drive the fine parte of the material through the sieve, an outlet spout at the lower end of the sieve to carry oli' the coarse parts of the material therefrom, said collecting cone having air inlets above the bottom of the chamber, and an air exhausting device communicating with the upper part of the chamber to create an air currentfrom the inlets through the bottom of the chamber into the annular passage and against the sifted material for the purpose specified.

EMIL LUDWIG HERMANN BAUERMEISTEK. llitnesses F. A. MAX KAEMPFF, ERNEST H. L. MUMMENHOFF.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

